The expression $20l + 25g - 10$ gives the number of dollars that Josie makes from mowing $l$ lawns and raking $g$ gardens. How many dollars does Josie make from raking $4$ gardens and mowing $3$ lawns?
Josie raking ${4}$ gardens and mowing ${3}$ lawns tells us that $g={4}$ and $l={3}$. Let's substitute $g={4}$ and $l={3}$ into the expression and evaluate: $\begin{aligned} &\phantom{=}20l + 25g -10\\\\ &= 20({3})+25({4}) - 10\\\\ &= 60 + 100 - 10\\\\ &= {150} \end{aligned}$ Josie makes ${150}$ dollars from raking $4$ gardens and mowing $3$ lawns.